[c-nsp] Preloading AS to static network entry via route-map:Duh?

[Arie Vayner (avayner)]

Just to complete my answer, and build on top of Artyom's comment, you
could use your route-map on the network statement to push a community
value which has a meaning of how many prepends you with to push on the
route. 
Then, on the egress eBGP session, match on the community, and add the
prepend.

This actually allows a great flexibility, as you may have multiple
communities for different prepend lengths, or even for different kinds
of eBGP sessions (customers, peers, upstreams).

Arie

-----Original Message-----
From: cisco-nsp-bounces at puck.nether.net
[mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Arie Vayner
(avayner)
Sent: Monday, January 17, 2011 20:28
To: Elmar K. Bins; cisco-nsp at puck.nether.net
Subject: Re: [c-nsp] Preloading AS to static network entry via
route-map:Duh?

If you take a look at the command reference for the as-path command:
http://www.cisco.com/en/US/docs/ios/iproute_bgp/command/reference/irg_bg
p4.html#wp1136246

You would see that the "prepend" keyword would work only on ingress or
egress BGP route-maps:
"Appends the string following the keyword prepend to the autonomous
system path of the route that is matched by the route map. Applies to
inbound and outbound BGP route maps."

In the link above there are also details about specific 4-byte AS
support.

Arie

-----Original Message-----
From: cisco-nsp-bounces at puck.nether.net
[mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Elmar K. Bins
Sent: Monday, January 17, 2011 17:11
To: cisco-nsp at puck.nether.net
Subject: [c-nsp] Preloading AS to static network entry via route-map:
Duh?

Re guys,

the prefixes I give out are being rooted by "network" entries with
a route-map attached (like "network a.b.c.d/e route-map <rm>").

In that route-map, I'm simply prepending an ASN ("as-path prepend
<as>").

Well - that prepend never makes it to the outside world. Source ASN is
simply my ASN, the desired <as> is nowhere to be found.

Am I wrong in assuming it should work that way?

Oh, platform is an ASR1002, IOS-XE 12.2(33)XNC1t.

Didn't try my 7301s yet...

Elmar.

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